Gas motor engine



2 Sheets-Sheet 1.

, (No Model.)

N. A. OTTO.

GAS MOTOR ENGINE.

Patented Sept. 28, '1886.

(No Model.) 2 Sheets-Sheet 2.

N. A. OTTO.

GAS MOTOR ENGINE.

N o. 350,077. Patented Sept. 28, 1886.

N. Firms Plmnmuwgmpner. wmmgnm. n. c.

NTTED STATES PATENT Orrrcn.

NIOOLAUS AUGUST OTTO, OF COLOGNEON-THE-RHINE, ASSIGNOR TO THE GASAMOTORENFABRIICDEUTZ, OF DEUTZ-ON-TIIERIIINF, GERMANY.

GAS-MOTOR ENGINE.

SPECIFIATIGN forming part of Letters Patent No. 350,077, dated September 28, 1886.

Application filed May QT, 1984i. Serial No. 263,421.

(N'omodel.) Patented in England April 28,1856, No. 5,S(ll,and in Belgium Moy 13, 1886, No. maar.

To @ZZ whom, t may concern:

Be it known that 1', Nleomus AUGUsT OTTo, a citizen oi'Prussia,residing at Cologne -on-the- Rhine, in the Empire of Germany, have invented a newand useful Iniprovement in Gas- Hotor Engines, (for which I have obtained a patent in Belgium No. 73,097, dated May 13, 1886, and have iliade application for patent in Great Britain, No. 5,801, dated A pril 28,1S86,)

ro of which the following is a specification.

This invention relates to au improved construction of gas-motor engines, wherein a single-acting working-cylinder is combined with a pump for compressing` the airsupply and I5 pump for compressing the gas-supply in such manner that while the piston is being propelled by the pressure produced by the combnstion of a mixture ot' gas and air the airpnmp draws in a charge of air and the gas- ',10 pump draws in a charge of gas during a variworkiiig-cylinder, assisting in the expulsion orn the products of combustion, and then the compressed charge of gas is forced by the gaspump, together with the air, into the workingcylinder,so that by the time the working-piston has completed its instrokea chamber at the end ofthe cy linder is made to contain a compressed charge of combustible gas and air, which is richest in gas at the firing port, and which is then fired,so that the engine makes a` workingstroke at each revolution ol' the crank-shaft,

the engine-piston and the pistons of the air and gas pumps being all connected to one and the same crank, so as to make their strokes together. f The power oi' the engine is regulated by regnlati ng the gas-supply to the gaspump, this supply being entirely cut oft' when the normal speed of the engine is exceeded.

The accompanying drawings show a gas-engine constructed according to the above-def 4 5 scribed invention.

Figure 1 shows a sectional plan of the engine, the section through the slide being taken on the line c (l, Figs. 3 and 3, while the section through the same parts at Fi g'. 1 is taken on line a, l). Fig. 2 is a side View partly in section. Fig. 3 is an end view with the slide removed. Fig. 4 is a part plan showing the intermediate gasvalve in section. Fig. Sais a` front view of the slide-valve. Figs. 5 and G are vertical. sections taken, respectively, on lines h t', Fig. 3, and cfg, Fig. l. Figs. '7, S, and 9 show details of the cams; and Figs. 10 to 13 show diagrams oi' motion.

The piston ofthe workingcylinder 1 and the two coupled pistons ot' the air-pump cylinder 2 and of the gaspump cylinder 3 are connected to the crank-shaft et by means of connecting-rods, the cranks being set in the same direction and parallel to one another, forming one common crank, as shown. The workiug-cylinder 1 is generally similar in constructionto that of the Otto engine-that is to say, it is of greater length than the stroke ot' the piston-so that when the piston is at the end. of its instroke there is a space of material capacity between the latter and the back of the cylinder, which is to receive the eompressed eharge. In the air-pump and gaspump cylinders no more than the unavoidable so-ealled Lwaste spaces between pis tons and cylinder ends are left at end stroke. The valve-shaft 5 receives its motion from the crank-shaft in such a manner by gearing at 23 that it makes one revolution to one ofthe crank-shaft. The valve-shaftworks the slidevalve 6 by means 0l' a crank, 2J., and the exhanst-valve 7 oftheworking-cylinderby means ofthe requisite intermediate parts ol" known construction, and likewise the hall-governor S, which serves to regulate or to cut off the admission of gas into the gas-cylinder 23 by means of a gas-valve, l), acted on by a cam and suitable levers.

The mode of operation of this engine is as follows: Vhen the working-piston is at the end ot' its instroke, Fig. 1, the engine doing` its normal work, the rear space in the workingcylinder 1 is iilled with a compressed mixture of combustible gases or 'vapors and atmospheric air, and with a portion of the products ot combustion which had not been expelled. Toward the end of the just-completed stroke of the piston gas and air will have been admittedsimnltaneously to the space of 1 through the inlet-passage in such manner that when the piston attains the end of the instroke a richer explosivcmixture is present 5,; in the passage 10 than there is in the charging-space of 1, in which the explosive mixture has been diluted by a surplus of air and a portion of the residual products of combustion. The ignition of the mixture compressed vin the space of 1 is effected by a flame burning in a cavity, 22, of the slide 6. This llame, on being brought to the aperture of the passage 10, securely'effects the ignition of the richer mixture contained in the passage 10. The pressure produced by the combustion of the charge causes the working-piston to perform its outstroke, during which work will be performed by expansion and transmitted to the fly-wheel shaft. lDuring the same outstroke the piston of 2 draws atmospheric air` into the air-pump cylinder through. the passage 11, the cavity 21 in the slide 6, and through the pipe 12,which communicates with the surrounding atmosphere. The piston of the gascylinder 3, as a rule, draws in gas during a variable part of the stroke, or it may draw in no gas at all when no combustible charge is to be formed, in which case a partial vacuum will be produced in the gas-cylinder. The admission of the gas is controlled by a cam, 25, Fig. 8, acting on a bell-crank level', 13, and causing it to open the gas-admissionvalvcf) at the commencement ofthe suction period. The gas from the valve 9 passes through the counection-pipe 141. and through the cavity 1 5 in the slide to the intermediate valve, 1G, and this being heldr'open during the suction period it passes on through the pipe 17 to the gas-pump. -During this time the slide-valve 6 has' been moving in the direction ofthe arrow, (see slidevalve diagram Fig. 10,) so that at the end of the suction period the slide has again attained the position shown on the drawings. The quantity of gas to be admitted can be varied at pleasure for the purpose of regulating the power of the engine by means of the oblique cam 25, (shown in Fig. 8,) which, by the action of the ball-governor 8, causes the gasvalve 9 to be held open either during thewhole stroke or only a part of it, according to its relative position on the shaft,in a similar manner to `the gas-admission cam of the Otto eugine. lll/'hen the pistons have attained the end of their outstroke, `they commence simultaneously their return-stroke in the three cylinders under the following circumstances: rlhe piston of the Working-cylinder 1 expels the products of combustion, discharging them into the atmosphere through the exhaust-valve 7, Which has been made to open for this purpose. At the same time the slide-valve 6, which at thisvmoment is in the position shown in Fig. 1,begins to establish a communication between the air-cylinder 2v and the cylinder-space of 1 by means of the passage 11, the cavity 2l in the slide, and the passage 10. The atmospheric air previously drawn into the cylinder 2 is now forced into the cylinder 1 by the piston and assists in the expulsion of the residual products of combustion contained in the cylinder 1 and partly mixes with them. In the gas-cylinder 3 the gas will be compressed, if gas has previously been drayvn in during the Whole stroke, the intermediate valve, 16, being closed; but if gas has been drawn in during part of the outstrokc only, the partial vacuum produced will be equalized and the Awork expended previously in producing a vacuum will be given out again. The exhaustvalve 7 of the working-cylinder l is made to close at about one-half of the stroke of the piston by means of a cam, 26, Fig. 9, on the valve-shaft and suitable levers. As soon as the exhaust-valve 7 has closed, the intermediate valve, 16, is opened by means of the cam 18, Fig. 7, and the bell-cranklever 19, Fig. 3, so that the gas from the gas-cylinder 3 may pass through the pipe 17 lo the intermediate valve, 16, which has been opened, thence to the cavity 15 in the slide and to the passage 20 in the slide-cover, thence to the cavity 2l in the slide, and, finally, to the inlet-passage 10 of the Working-cylinder, and into the cylinder itself. In this engine therefore by the action of the air and g'. s pumps irst fresh air and afterward during the remaining part of the instroke gas together with air are admitted through the passage 10 into the compression-space 1. rlhe mixture thus stored up lin the passage 10 and cylinder-space 1 is thus compressed by the joint action of the three pistons until these have attained the end of theirinstroke. When the working-piston has arrived at the end of its instroke, ignition is effected, and the above-described cycle of operations begins again, so that in this engine an explosion takes place at every revolution of the crank-shaft. The operations in the three cylinders during one revolution of the crank are 'represented diagrammatically in Figs. 11, 12, and 13. 'l

The above-described construction of engine lembodies the following advantages, which are peculiar to it: It admits of an almost perfect expansion of the gases, which are at a high 'pressure vafter combustion, the degree of ex- Ils pansionv depending on the ratio which the volume of the charging or compression space is made to bear to the volume swept through by the piston of the Working-cylinder.l Alth ugh the capacities of thegas and air pumps ave to be in a suitable proportion to the capacity of the charging-space, yet, by varying 'the time when. the exhaust-valve closes and the gas-valves open, the quantity and composition of the charge can be regulated at pleasure. The efiieiency of this engine will therefore Vbc of a very high degree. y

The mode of regulating this engine by introducing more or less gas into the charge produces a very high degree of uniformity in the Working of the engine. The ignition is rendered very secure, even with weak charges, in consequence of astrong-explosive mixture being always present in the inlet-passage. Moreover, in consequence of the airpump forcing rst pure air through the workingcylinder after the explosion and working stroke have been effected, the cylinder is cooled and the residuary products of combustion are expelled, so that when the gas enters the cylinder no premature ignition can be caused.

Having thus described the nature of my `invention and the best means I know for carrying the same into practical effect, I claim- 1. ln a gas-motor engine, the combination of a single-acting working-cylinder with an air-pump and a gas-pump, the pistons of said air and gas pumps performing their strokes in time with the working-cylinder piston, the air-pump drawing in its charge during the working outstroke of the engiuepistou and discharging its contents into the engine-cylinder during the entire instrokc of the enginepiston, so as to assist in the expulsion ot' the products ot' combustion and allow the escapevalve to be closed at about one-halt' the instroke of the engine -`piston, while the gaspump draws in a variable charge during the outstroke of the engine-piston and Vforces that charge into the engine-cylinder after the closing ot' the escape-valve and while the charge ot' the engine-cylinder is being compressed by the completion ot' the instrokes ot' the enginepiston and air-pump piston, substantially as herein described.

2. In a gas-motor engine, the combination, with the working-cylimler 1, ot' an air-pump, 2, moving in time with the engine-piston and connnunicating with the cylinder 1 through passages 10 and 11 and cavity 2l ot' slide 6, making one to-aud-fro motion for each revolution of the crank-shaft, the pump 2 drawing in a charge, of air while the engine-piston perl'orms its working outstroke and t'orcing that charge into the engine-cylinder through the slide-valve during th'e return-stroke, during theiirst partot' which the products of combustion are expelled through au escape-valve, while during the last part the charge ot' air introduced is compressed, substantially as herein described.

f. lu a gas-motor engine, the combination, with the engine-cylinder 1, ot' a gas-pump, 3, moving in time with the engine-piston and communicating with the gas-supply valve 9 through pipe 14, slide-cavity 15, valve 16, and pipe 17, and with the cylinder 1 through pipe 17. valve 16, and slide-cavity 15, the pump l being made to draw in a variable charge ol' combustible gas while the enginepiston performs its outstroke, then to compress thecharge during the lirst part ol.' the iustroke ol' the engine-luston, and, lastly, to deliver the charge into the engine-cylinder during the last part ot" the pistons inst roke, substantially as herein described.

4. 1u a gas-motor engine, the combination ot' a working-cylinder, 1 with inlet-port 10, an air-pump, 2, with passages 11 12, a gaspump, 3, with passage 17 andvalve 16, and a slide, 6, with cavities 15, 20, and 21, whereby charges ol.' air and gas are drawn separately through the slide into the air and gas pumps, the charge ot' air being then delivered from the air-pump through the engine-slide into the engine-cylinder, alter which the charge of gas is delivered in a compressed state from. the gas-pump through the slide into the enginecylinder, substantiallyv as herein described.

5. In a gas-motor engine, a gas-pump receivin g a charge ot' gas through a regulatingvalve and delivering such charge into the cylinder through an intermediate valve actuated by a cam on the slide valve shalt, said intermediate valve being opened by the cam to allow the charge ol'gas to pass to the working cylinder after the gas-pump has performed part of its stroke, substantially as and for the purposes herein described.

In testimonyr whereot I have signed my name to this specification, in presence ol two subscribing witnesses, this Sth da)v ol' Nay, A. D. 18%.

NIGOLAUS A'U GU ST OTTO.

\Vitnesses:

GUs'rA'vn Annun'r Onmrclls, 1 irri-:n LANL; nu. 

